docs: def after_init_apps(sender):
      """
      Check redis version
      """
      from uliweb import settings
      from uliweb.utils.common import log
      
      check = settings.get_var('REDIS/check_version')
      if check:
          client = get_redis()
          try:
              info = client.info()
          except Exception as e:
              log.exception(e)
              log.error('Redis is not started!')
              return
          
          redis_version = info['redis_version']
          version = tuple(map(int, redis_version.split('.')))
          op = re_compare_op.search(check)
          if op:
              _op = op.group()
              _v = check[op.end()+1:].strip()
          else:
              _op = '='
              _v = check
          nv = tuple(map(int, _v.split('.')))
          if _op == '=':
              flag = version[:len(nv)] == nv
          elif _op == '>=':
              flag = version >= nv
          elif _op == '>':
              flag = version > nv
          elif _op == '<=':
              flag = version <= nv
          elif _op == '<':
              flag = version < nv
          else:
              log.error("Can't support operator %s when check redis version" % _op)
          if not flag:
              log.error("Redis version %s is not matched what you want %s" % (redis_version, _v))